Automatic drill head



March 22, 5 c. AT QN I 1,850,299

AUTOMATI C DRILL HEAD Filed Oct. 10, 1928 4 Sheets-Sheet l INVENTOR.

A TTORNEY.

I gdneg Qwai-son BY m2 March 22, 5 c WATSON AUTOMATIC DRILL HEAD 1928 4 Sheets-Sheet 2 Filed Oct. 10

I NI"'ENTOR. qc'lney C. Wacson ATTORNEY.

March 22, 1932; s W T 1,850,299

AUTOMATIC DRILL HEAD Filed Oct. 10. 1928 4 Sheets-Sheet 3 FiG. 5.

16 F is m] I! "/9 3 k INVENTOR.

gdney C.Wacson AT-TORNEY.

March 22, 1932. 5, c, w TsQ 1,850,299

AUTOMATIC DRILL HEAD Filed Oct. 10, 1928 4 Sheets-Sheet 4 INVENTOR.

A TTORNE v d gy GWatson Patented Mar. 22, 1932 UNITED S ATES PATENT OFFICE.

SYDNEY C. WATSON, OF DETROIT, MICHIGAN, ASSIGNOR TO THE BRADFORD MACHINE TOOL COMPANY, OF CINCINNATI, OHIO, A CORPORATION OF OHIO 44 of Fig. 1, parts appearing in elevation;

AUTOMATIC DRILL HEAD Application filed October 10, 1928. Serial No. 311,698.

My invention relates to automatic drill heads and more particularly to the feed clutch mechanism, including the means for tripping same; the positive cam control withthe cam roller mounted directly in the quill; and the means for driving the cam from the periphery instead of the center. I

The objects of my invention are to provide a drill head which is simple, efiicient, economical to manufacture, automatic in its operation and having a rapid approach and return of the spindle.

My invention consists in the construction, combination, location and arrangement of parts, as herein set forth and claimed.

In the drawings:

Fig. 1 is a side elevation of a drill head embodying the invention;

Fig. 2 is an end elevation thereof looking towards the spindle;

Fig. 3 is a vertical longitudinal sectionv taken on a plane corresponding to line 3-3 of Fig. 2, with parts of the spindle and clamping rod appearing in elevation;

Fig. 4 is a vertical cross section on the line Fig. 5 is a vertical cross section on the line 55 of Fig. 1, parts appearing in elevation;

Fig. 6 is an elevational detail'of the feed cam;

Fig. 7 is a fragmental vertical cross section through the roller, quill and part of the feed cam, on the line 77 of Fig. 3, with parts appearing in elevation; and K Fig. 8 is a vertical section taken on the line 8-8 of Fig. 3, the cam shaft shown in elevation.

Referring to the drawings, the particular machine chosen for disclosure of an embodiment of the invention comprises frame or bed 1, spindle 2, motor 3, starting lever 4 and emergency lever 5, as clearly shown in Fig. 1.

Spindle drioefReferring to Fig. 3, the spindle shaft 6 is driven directly from motor 3 through gear 7 and sleeve 8. Said sleeve 8 is rotatably mounted within bearings 9, which bearings are supported within bed 1. The inner end of spindle shaft 6 is splined within the sleeve 8 and is adapted to have a longitudinal reciprocating motion therein during the forward and return strokes of the spindle 2. The gear 7 is keyed to the outer end of sleeve 8 and held against disengagement therefrom by nut 10.

Positive cam c0nt1'oZ.-The forward and return strokes of spindle 2 are cont-rolled by 'a positive cam action. This mechanismcom prises quill 11, slidably mounted within bed 1., cam roller 12 and feed cam' 13. The feed 'cam 13 is rotatably mounted upon stud 14 proach and return of the spindle 2 is effected during each complete revolution of said feed cam 13. and the track may be arranged to produce any variation of the spindle travel that may be desired. The cam roller 12 is rotatably mounted upon stud 17' (Fig. 7) which stud is carried directly by the quill 11 and held therein'by nut 18. A clamping rod 19 is also rigidly fixed and carried by quill 11, as clearly illustrated in Figs. 3 and 7, respectively, and the purpose of this clamping rod is to operate any auxiliary clamping attachment or other mechanism that may require the use of a reciprocating motion in conjunction with the travel of the spindle.

Feed cam drioe..-Tl1e feed cam 13 has teeth out on its outer periphery forming gear 20, which gear is driven from motor 3, through pinion 21 (Fig. 5) gear 22, gear 23, clutch members 24-25, worm gear 26 and worm 27, the latter being'integrally formed with sleeve 8, as shown in Fig. 3.

Pinion 21 is integrally formed on one end of shaft 28, the latter being rotatably mount ed in bed 1 (Fig. 5) and gear 22 is mounted upon said shaft and in permanent mesh with gear 23.

Overload or safety 0Zutch.'-Ordinarily,

the gear 22 is pinned to shaft 28 by a shear pin (not shown) but I prefer to have a collar by heavy coil spring 32. Collar 33 is adapted to be forced against spring 32 by nut 34 to increase the tension of said spring against collar 29. Should the spindle ever become overloaded, all moving parts of the drill head and the motor 3will be protected from any damage, due to the fact that the clutch teeth 30-31 will slip past each other, thus stopping the drive to the feed cam. Should the teeth 30-31 slip during normal operation of the drill head, simply take up on nut 34, thereby increasing the tension of coil spring 32 against collar 29.

Emergency Zeoer.-As clearly shown in Figs. 1, 2 and 4, respectively, the emergency lever 5 is pivotally mounted upon pin 35 and is vertically arranged upon the outside of bed 1 and between said bed and starting lever 4. That portion of the lever 5, above pin 35, is forced in an outward direction or away from bed 1 by coil spring 36, thus the lower end 5a of lever 5 is forced inwardly towards bed 1, and the screw 37, carried by said lower end 5a of lever 5, is forced against the outer end or rod 38. As clearly shown in Fig. 4, rod 38 is horizontally disposed and slidably mounted within bed 1, and coil spring 39 encircles said rod and fits between the outer wall 1a of bed 1 and collar 40, said collar being pinned to said rod 38, thus exerting inward pressure on said rod 38 through said collar 40, so that said collar normally rests against the face of wall 1?). The emergency lever 5 is also provided with an extended portion or shelf 56, which is adapted to receive and support lug 4a, formed integral with starting lever 4.

The starting Ze'v'er'.-The starting lever 4 is fixed to the outer end of sleeve 41 by stud bolt 42, as clearly shown in Figs. 1 and 5, respectively, and the inner end of said sleeve is provided with a plurality of inclined projections or teeth 43. v

The sleeve 41 is slidably mounted within cover plate 44 and one end of shaft 45 is rotatably mounted within said sleeve (Fig. 5). The inner surface of cover plate 44 is provided with a plurality of inclined teeth 46, arranged for wedging engagement with the inclined teeth 43. Gear 23 and clutch member 24, respectively, are keyed toshaft 45 and are locked against the shoulder 54 by nut 53. A bearing 47 is inserted between said gear 23 and the inner end of sleeve 41, as shown in Fig. 5. Clutch member 25 is keyed to worm gear 26 and said clutch member is rotatably mounted upon bearing stud 48, as clearly shown in Fig. 5, said stud being anchored within bed 1 by nut 49. The inner endof shaft 45 is j ournaled within socket 50 of bearing stud 48 and is countersunk to re ceive the ball 51. Coil spring 52, received by socket 50 (in bearing stud 48) rests against the bottom of said socket and forces outward on said ball 51, which ball, in turn, forces outward on shaft 45. This outward thrust on shaft 45 by spring 52 and ball- 51 holds the clutches 2425 out of engagement with each other when the starting lever 4 is in the dropped or inoperative position shown by dotted lines'inFig. 1. Whenever the starting lever 4 is drawn upwardly, as shown by full lines in Fig. 1, the wedging engagement of inclined tceth 4346 overcomes the tension of spring 52, thereby engaging the clutch members 24-25, as heretofore described.

Operat2'0n.Referring now to the operation of my improved drill head, let us assume that the motor 3 is running at a selected speed. As the motor 3 is suitably connected to gear 7 it will, therefore, be apparent that said gear will also be in motion, or, in other words, revolved in a clockwise direction. As sleeve 8 is fixed to gear 7, said sleeve will revolve in unison with said gear. As before stated, spindle shaft 6 is slidably splined within sleeve 8; therefore, said shaft will revolve in unison with said sleeve and thus the drive from motor 3 to spindle 2 is accomplished. Whenever the motor 3 is running, the spindle shaft 6 and spindle 2 are revolved in aclockwise or anti-clockwise direction depending upon the direction of rotation of said motor. Referring to Fig. l, the normal position of starting lever 4 is shown by broken lines and is held in this lowered position by spring 55. To start the feed cam 13, thereby imparting a reciprocating movement to spindle 2, simply proceed as follows:

Raise the starting lever 4 until the lug 4a thereof engages the shelf 55 of emergency lcver 5, thereby holding said starting lever in a raised position, as shown by full lines in Fig. 1. This upward movement of starting lever 4 causes the sleeve 41, carrying the teeth 43, and rotatably mounted on shaft 45 to have a partial rotation and to be moved inwardly, due to the inclined teeth 43 engaging'the inclined teeth 46 on cover plate 44,

which, in turn, forces bearing 47, gear 23 and clutch member 24 inwardly with shaft 45, overcoming the tension of spring 52, and thus engaging the clutch member 24 with clutch member 25, thereby connecting gear 23 with worm gear 26. Therefore, when the starting lever 4 is raised upwardly the clutches 2425 will be engaged with each other and the feed cam 13, driven from motor 3, through gear 7, sleeve 8, worm 27, worm gear 26, clutches 2524, gear 23, gear 22, clutch collar 29, shaft 28, pinion 21 and gear 20, respectively, as clearly shown in Figs. 3 and 5. Each complete revolution of the feed cam 13 moves the spindle 2 from its extreme inner position within bed 1 to its extreme outer position and back to the extreme inner position. This outward and inward movement of the spindle 2 is caused by the movement of cam roller 12 within cam track 16, said roller being rotatably mounted upon the quill 11.

The feed cam: 13 is provided with an obstruction 13a, which obstruction is adapted to engage the inner end of rod 38 and is adapted to force it outwardly, whereupon the outer end of said shaft is adapted to push against screw '37 and thereby move the emergency lever 5, so that shelf 51) will be disengaged from lug 4a of starting lever 4, thus allowing coil spring 55 to draw the lever downwardly to the dotted position vshown in Fig. 1, which, in turn, disengages the clutch member 24-25, thereby discontinuing the drive to the feed cam 13. If it is desired to impart continuous motion to the feed cam 13, simply unscrew screw 37 a suflicient dis tance so that the outer end of rod 38 will not strike said screw,.thus preventing the release of emergency lever 5.

An advantage of this invention is that the feed cam' 13 can be continuously driven by motor 3, or, if desired, it may be stopped after each revolution by the trip mechanism, as heretofore explained.

Another advantage of this invention is the manner in which the feed camjis driven from its periphery instead of its center, as has been the general practice heretofore, thus creating a larger volume of available power for the operation of 'the feeding mechanism with a reduced'input of power from the motor than has heretofore been made possible.

Still another advantage is the positive cam action and roller mounted directl in the quill. This is not only a strong an durable therein, a spindle sha trotatably mounted in said quill, a sleeve splined to said shaft and rotatably mounted within said bed, driving means for said sleeve, a worm formed on the outer periphery of said sleeve, a worm gear rotatably mounted within said bed a d in permanentmesh with said worm, a clutch ;member fixed to said worm gear, a second clutch member adapted to slidably engage said first-mentioned clutch member, a clutch gearadapted to be rotatably mounted within said bed and held in permanent mesh with said last-mentioned gear, a clutch collar, means for holding said clutch collar in engagement with said blutch gear, a shaft r0.-

from the scope or of said feed cam adapted to permanently mesh with said last-mentioned pinion, an

irregular track formed within said feede'am,

aroller rotatably mounted upon said quill and adapted to be inserted within said track, a starting lever adapted to engage or dlsengage said first .and second-mentioned clutches whereby the drive from said worm to said feed cam is completed or severed, dependin upon the position of said startlng lever, an means carried by said feed cam and bed whereby said starting lever may be released,

thereby releasing or' disengag ng said first and second-named clutch members after each complete revolution of said feed cam.

2. An automatic drill head, as specified inand adapted to engage one end of said pin,

a spring adapted to normally hold said pin inwardly 'so asto,be in the path of said dog, the other end of said pin adapted to engage the lower end of said emergency lever when I said dog moves said pin outwardly from within said bed to thereby cause said emergency lever'to release said startinglever thus severing the drive from said worm to said feed cam by the disengagement of said first and second-mentioned cl tch members.

' SYDNE- C; WATSON.

tatabl mounted within said bed and splined,

.tosai clutch gear, apinionfixed to one end of-saiid'sha'ft, a feed cam rotatably mounted within said bed, teeth on theouter periphery iao 

